The usual suspects?
06-20-2013, 11:06 PM
#1
11 Second Club
Thread Starter
The usual suspects? What should be looked for after a stock rocker arm pukes its needle bearings? It seems that there could be something that caused it other than poor design, or is it just me? Out of 3 LS1's we have owned, 2 have lost rockers. The first one broke the ball on the bottom of a lifter too and wiped out the block.
Our current engine always had a slight tick to it that was only noticeable after the oil was hot, and small air bubbles in the oil after being run hard. It seemed to get worse over the 10,000 or so miles we drove it before a rocker arm started beating on the valve cover. It lost some needle bearings. We had the trunion upgrade done and also swapped the prc dual springs for some Brian Tooley .660's. The tick is much better now (it has always sounded like Just 1 lifter) but it's still there and over the 1,000 or so miles we have been running it, seems to be getting slightly louder. The car does stumble a little when coming to a stop and another constant has been a slight vibration noticeable when revving the engine that feels like a very slight miss. The car did 445 rwhp so it's hardly crippling it but is succeeding in driving me nuts waiting for the next breakage. Heads are PRC 5.3 stage 2.5's, Torquer 2 cam, and 7.4 hardened pr's.
Suggestions?
Our current engine always had a slight tick to it that was only noticeable after the oil was hot, and small air bubbles in the oil after being run hard. It seemed to get worse over the 10,000 or so miles we drove it before a rocker arm started beating on the valve cover. It lost some needle bearings. We had the trunion upgrade done and also swapped the prc dual springs for some Brian Tooley .660's. The tick is much better now (it has always sounded like Just 1 lifter) but it's still there and over the 1,000 or so miles we have been running it, seems to be getting slightly louder. The car does stumble a little when coming to a stop and another constant has been a slight vibration noticeable when revving the engine that feels like a very slight miss. The car did 445 rwhp so it's hardly crippling it but is succeeding in driving me nuts waiting for the next breakage. Heads are PRC 5.3 stage 2.5's, Torquer 2 cam, and 7.4 hardened pr's.
Suggestions?
06-21-2013, 01:22 AM
#2
Get a different cam and stiffer pushrods. The Torquer 2 is an XE-R cam. Get something with LXL or EPS lobes so it won't beat the **** out of the valvetrain.
Also, move to a much stiffer pushrod. Manton 11/32 is the minimum I'd run.
You're probably getting valve loft, and the lifter is crashing down on the cam, which beats the rockers and lifters senseless. It also can severely damage a cam. It happens with too aggressive a lobe meets too flimsy a pushrod. Then, you have a spring trying to control all the shenanigans, and it's connected to too heavy of a valve - upping the spring pressure just puts more stress on the lifters, pushrods, and rockers. And the wear happens over time as you're seeing.
Since you probably don't want to invest in swapping out the valves in the heads for something much lighter (and much more expensive), the pushrods and cam offer the easiest upgrade path. I'd also maybe look at some beefier lifters that have larger rollers like the Morel 5206.
Also, move to a much stiffer pushrod. Manton 11/32 is the minimum I'd run.
You're probably getting valve loft, and the lifter is crashing down on the cam, which beats the rockers and lifters senseless. It also can severely damage a cam. It happens with too aggressive a lobe meets too flimsy a pushrod. Then, you have a spring trying to control all the shenanigans, and it's connected to too heavy of a valve - upping the spring pressure just puts more stress on the lifters, pushrods, and rockers. And the wear happens over time as you're seeing.
Since you probably don't want to invest in swapping out the valves in the heads for something much lighter (and much more expensive), the pushrods and cam offer the easiest upgrade path. I'd also maybe look at some beefier lifters that have larger rollers like the Morel 5206.
06-21-2013, 10:58 PM
#3
11 Second Club
Thread Starter
That makes a lot of sense but if it results from too aggressive a lobe meeting too flimsy a push rod.... couldn't I just replace the too flimsy a push rods with the ones you suggested? Not intended as a smarta#$ question. Just kinda seems like a possible fix. I love the cam and performance other than this issue.
On a side note, what kind of times does yours run? Great looking car and set up.
On a side note, what kind of times does yours run? Great looking car and set up.
06-21-2013, 11:06 PM
#4
You could try the stiffer pushrods. That'd probably solve a good bit of it. You'd just be swapping a cam with similar valve events, so you wouldn't notice much. Maybe a slightly smoother idle for example. Manton 11/32nd run about $159, but they are true length, not gauge length like Comp or Trend pushrods, so make sure you measure the actual length of the pushrod checker not just what it tells you since that's the gauge length.
And I'm in the process of putting my car together. I'm hoping I can squeeze some 10s out of it.
And I'm in the process of putting my car together. I'm hoping I can squeeze some 10s out of it.